US5152783A - Antithrombogenic material - Google Patents
Antithrombogenic material Download PDFInfo
- Publication number
- US5152783A US5152783A US07/570,614 US57061490A US5152783A US 5152783 A US5152783 A US 5152783A US 57061490 A US57061490 A US 57061490A US 5152783 A US5152783 A US 5152783A
- Authority
- US
- United States
- Prior art keywords
- antithrombogenic
- ions
- functional groups
- silicone material
- sioh
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L33/00—Antithrombogenic treatment of surgical articles, e.g. sutures, catheters, prostheses, or of articles for the manipulation or conditioning of blood; Materials for such treatment
- A61L33/0076—Chemical modification of the substrate
- A61L33/0082—Chemical modification of the substrate by reacting with an organic compound other than heparin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
- B29C59/16—Surface shaping of articles, e.g. embossing; Apparatus therefor by wave energy or particle radiation, e.g. infrared heating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
- B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
- B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
- B29C35/0866—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using particle radiation
- B29C2035/0872—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using particle radiation using ion-radiation, e.g. alpha-rays
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2083/00—Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material
Definitions
- This invention relates to an antithrombogenic material employed in artificial biocompatible material, such as an artificial blood vessel, or in medical equipment brought into contact with blood.
- antithrombogenic materials such as polyurethane-silicone block polymers, heparinated high molecular materials, hydroxy ethyl methacrylate-styrene block polymer, urokinase immobilized high polymer material or plasma treated high molecular weight materials, for use in various fields of applications.
- the first to fourth of these antithrombogenic material are prepared by chemical synthesis through various steps such as material refining or separation for synthesis with resulting inconveniences in productivity, equipment investments and costs.
- the fifth material which may be produced by physical processes, has a drawback that it presents a non-homogeneous treatment surface.
- the conventional antithrombogenic materials leave much to be desired in that the manufacture process is complicated or the product of a uniform quality cannot be produced without considerable difficulties.
- the antithrombogenicity material of the present invention is characterized in that its surface has been modified by ion implantation and in that it consists of a silicone material which has its surface modified by introducing functional groups on its surface by ion implantation.
- compatibility to blood may be markedly improved by the introduction of the functional groups by ion implantation and by the doping effect of the implanted elements.
- FIG. 1 shows the Fourier Transform Infrared Spectrometry Attenuated Total Reflection (FT-IR-ART) spectrum on the silicone surface layer implanted with ions.
- FT-IR-ART Fourier Transform Infrared Spectrometry Attenuated Total Reflection
- FIGS. 2A and 2B are charts showing the degree of platelet accumulation on the main organs of rats supplied with ion-implanted samples and on the samples in terms of the count ratio as measured with a scintillation counter.
- the present inventors have conducted eager searches for accomplishing the above object and reached the conclusion that ion implantation is highly effective in improving antithrombogenic.
- the antithrombogenicity material of the present invention has been fulfilled on the basis of the above finding and is characterized in that the material has its surface modified by ion implantation.
- an antithrombogenicity material having superior compatibility with blood may be produced by modifying the silicone material through ion implantation.
- ion species such as O 2 + , H + and N 2 + are preferred for implantation, such ions as He + , C + , N + , O + , Ne + , Na + , Ar + or K + may also be employed.
- the amount of ions implanted and the energy for acceleration may be optically selected in dependence upon the usage or the species of the ions, they are usually selected to be in the range of about 1 ⁇ 10 12 to 3 ⁇ 10 17 cm -2 and in the range of tens to hundreds of keVs, respectively.
- the possible reason for the improved antithrombogenic due to ion implantation is the introduction of a various functional groups into the artificial material, such as the silicone material, by the irradiation of the ion beams.
- the following Table 1 shows the species of functional groups generated in the silicone as a result of the ion implantation. Although OH groups are produced by implantation of any ion species, it is not clear if this is directly related with the antithrombogenic.
- H + , O 2 + and N 2 + were implanted in a silicone intended for medical use to test the compatibility thereof with the blood.
- a silicone sheet for medical use produced by the Toshiba Silicone Co. Ltd., was used as the material to be modified by ion implantation.
- This silicone sheet has been prepared by thermally vulcanization cure of a polymer having a siloxane linkage Si-O in its main chain and side methyl chains CH 3 , as shown in the following structural formula, in the presence of a Pt catalyst: ##STR1##
- H + , O 2 + and N 2 + ions were implanted at an acceleration energy of 150 keVs.
- the ion beam current of not more than 1 ⁇ A/cm 2 was used to suppress a temperature rise in the sample.
- the amount of ions implanted was selected to be 2 ⁇ 10 17 cm -2 and 1 ⁇ 10 17 cm -2 , for the ion species of H + and O 2 + or N 2 + , respectively.
- the samples irradiated with the ion beam undergoes a variety of physical and chemical changes.
- measurements were made of the amounts of decomposition of the siloxane linkages and methyl groups as well as the superficial functional groups by the Fourier Transform Infrared Spectrometry Attenuated Total Reflection (FT-IT-ATR) method.
- FT-IT-ATR Fourier Transform Infrared Spectrometry Attenuated Total Reflection
- FIG. 1 shows a spectrum by FT-IR-ATR of a sample into which ions have not been implanted and a sample into which ions have been implanted for the wavelength range of 1300 to 4000 cm -1 .
- a rat was used as a laboratory animal. After platelets marked with a radioactive isotope (In- 111 -tropolone) were intravenously administered to the rat under anesthetization, the ion-implanted sample was introduced into the superior vena cava via common carotid and retained there for two days.
- a radioactive isotope In- 111 -tropolone
- the rat was then killed by loss of blood on heparin administration and the ion-implanted sample was well as the main organs were extracted. Using a scintillation counter, the radioactivity, i.e. the count ratio with respect to blood per unit weight, was measured of these samples and the main organs and the state of accumulation (formation of blood clots) was observed. Marking of the rat's platelets by In- 111 -tropolone was performed in accordance with the Dewanjee et al's method.
- FIGS. 2A and 2B show the count ratio of the In- 111 -tropolone-platelet samples and the organs in rats not supplied with artificial blood vessel samples in the blood, rats supplied with artificial blood samples not implanted with ions, and rats supplied with artificial blood vessel samples implanted with ions, with respect to the samples and the organs.
- platelet accumulation is markedly decreased on the sample surface with H + ion implantation while it is markedly decreased not only on the sample but also in the superior vena cava with O 2 + implantation.
- platelet accumulation is decreased on the sample surface, it tends to be decreased in hearts, kidneys or livers as well, whereas, when platelet accumulation is decreased on the sample surface and in the superior vena cava, it is similarly decreased in the main organs.
- thrombus on the artificial material itself is suppressed, and platelet accumulates on the blood vessel wall.
- platelet accumulation on the blood vessel wall occurs to the same extent, whereas platelet accumulation on the liver occurs to a lesser extent. It may be seen that platelet accumulation on the intrafiler organs may be decreased due to the lesser damage inflicted on the platelets by contact with the artificial blood vessel samples.
- the antithrombogenic material of the present invention exhibits superior compatibility to blood and affects the spleen, kidney or liver to a markedly lesser extent. This means that the damages done to the platelets within the living body have been decreased, which is of critical significance in not disturbing the living body system.
- the antithrombogenic material of the present invention is manufactured by a surface treatment technique under thermally unbalanced conditions without employing chemical synthesis, so that no complicated process is necessitated with obvious advantages in productivity.
- the direct effect is achieved while the uniformity and controllability are also excellent, since the interaction between the ion beam and the solid material is resorted to.
- the antithrombogenic materials of the present invention may be manufactured easily by surface modification, and antithrombogenic may be advantageously improved by application to existing medical appliances.
Landscapes
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Hematology (AREA)
- Surgery (AREA)
- Epidemiology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Materials For Medical Uses (AREA)
- Laminated Bodies (AREA)
- Prostheses (AREA)
Abstract
Description
TABLE 1 ______________________________________ ion species introduced functional groups ______________________________________ H.sup.+ SiOH, He.sup.+ SiOH, SiH C.sup.+ SiOH, SiH, >C═O N.sup.+ SiOH, SiH, amine O.sup.+ SiOH, SiH, >C═O Ne.sup.+ SiOH, SiH, Na.sup.+ SiOH, SiH, CH.sub.2 carboxylate N.sub.2.sup.+ SiOH, SiH, CH.sub.2 amine O.sub.2.sup.+ SiOH, SiH, CH.sub.2 >C═O K.sup.+ SiOH, CH.sub.2 1560 cm.sup.-1 Ar.sup.+ SiOH, SiH, CH.sub.2 ______________________________________
Claims (15)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1250523A JP2930329B2 (en) | 1989-09-28 | 1989-09-28 | Antithrombotic material |
JP1-250523 | 1989-09-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
US5152783A true US5152783A (en) | 1992-10-06 |
Family
ID=17209159
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US07/570,614 Expired - Lifetime US5152783A (en) | 1989-09-28 | 1990-08-21 | Antithrombogenic material |
Country Status (3)
Country | Link |
---|---|
US (1) | US5152783A (en) |
JP (1) | JP2930329B2 (en) |
CA (1) | CA2023964C (en) |
Cited By (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5308704A (en) * | 1991-08-20 | 1994-05-03 | Sony Corporation | Cell adhesive material and method for producing same |
US5334201A (en) * | 1993-03-12 | 1994-08-02 | Cowan Kevin P | Permanent stent made of a cross linkable material |
US5451428A (en) * | 1991-05-21 | 1995-09-19 | Hewlett-Packard Company | Method for pretreating the surface of a medical device |
WO1995031944A1 (en) * | 1994-05-20 | 1995-11-30 | Vec Tec, Inc. | Methods rendering grafts nonthrombogenic and substantially nonimmunogenic |
US5545208A (en) * | 1990-02-28 | 1996-08-13 | Medtronic, Inc. | Intralumenal drug eluting prosthesis |
US5607463A (en) * | 1993-03-30 | 1997-03-04 | Medtronic, Inc. | Intravascular medical device |
US5681575A (en) * | 1992-05-19 | 1997-10-28 | Westaim Technologies Inc. | Anti-microbial coating for medical devices |
US5837275A (en) * | 1992-05-19 | 1998-11-17 | Westaim Technologies, Inc. | Anti-microbial materials |
WO1998052623A1 (en) * | 1997-05-22 | 1998-11-26 | The Regents Of The University Of California | Ion-implanted protein-coated intralumenal implants |
US5851231A (en) * | 1990-02-28 | 1998-12-22 | Medtronic, Inc. | Intralumenal drug eluting prosthesis |
US5906824A (en) * | 1996-05-17 | 1999-05-25 | Sony Corporation | Antithrombogenic material and method for producing the same |
WO2002074354A1 (en) * | 2001-03-16 | 2002-09-26 | Delsitech Oy | Treatment of sols, gels, mixtures or composites of sols and gels, and/or sol-gel derived materials |
WO2002094332A1 (en) * | 2001-05-21 | 2002-11-28 | Qualimed Innovative Medizinprodukte Gmbh | Medical device |
WO2004026355A1 (en) * | 2002-08-30 | 2004-04-01 | Riken | Biological repair material compatible with biological tissue adhesive |
US20040121451A1 (en) * | 2001-03-16 | 2004-06-24 | Niko Moritz | Treatment of sols, gels and mixtures thereof |
US20040176838A1 (en) * | 2001-05-21 | 2004-09-09 | Andreas Mucha | Medical device |
US20060058835A1 (en) * | 1999-09-27 | 2006-03-16 | Yuichi Murayama | Bioabsorbable polymeric implants and a method of using the same to create occlusions |
US20070185570A1 (en) * | 2003-08-19 | 2007-08-09 | The Chemo-Sero-Therapeutic Research Institute | Material for aneurysm curing |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5636605A (en) * | 1994-06-22 | 1997-06-10 | Toyota Jidosha K.K. | Composite intake manifold for an internal combustion engine |
JP4327240B2 (en) * | 2006-08-31 | 2009-09-09 | 独立行政法人科学技術振興機構 | Printing method on resin molded body and thermoplastic resin molded body |
JP4906548B2 (en) * | 2007-03-15 | 2012-03-28 | 本田技研工業株式会社 | Intake manifold for multi-cylinder internal combustion engines |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3808113A (en) * | 1970-08-06 | 1974-04-30 | Zaidan Hojin Seisan Kaihatsu K | Method for manufacturing medical articles composed of various synthetic high polymers coated with collagen and exposed to radiation |
US3903891A (en) * | 1968-01-12 | 1975-09-09 | Hogle Kearns Int | Method and apparatus for generating plasma |
US3955012A (en) * | 1970-08-06 | 1976-05-04 | Zaidan Hojin, Seisan Kaihatsu Kagaku Kenkyusho | Method for manufacturing medical articles composed of silicone rubber coated with collagen |
US4718905A (en) * | 1986-08-13 | 1988-01-12 | Freeman Jerre M | Haptic element using ion beam implantation for an intraocular lens |
US4851009A (en) * | 1985-12-16 | 1989-07-25 | Corvita Corporation | Crack prevention of implanted prostheses |
-
1989
- 1989-09-28 JP JP1250523A patent/JP2930329B2/en not_active Expired - Fee Related
-
1990
- 1990-08-21 US US07/570,614 patent/US5152783A/en not_active Expired - Lifetime
- 1990-08-24 CA CA002023964A patent/CA2023964C/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3903891A (en) * | 1968-01-12 | 1975-09-09 | Hogle Kearns Int | Method and apparatus for generating plasma |
US3808113A (en) * | 1970-08-06 | 1974-04-30 | Zaidan Hojin Seisan Kaihatsu K | Method for manufacturing medical articles composed of various synthetic high polymers coated with collagen and exposed to radiation |
US3955012A (en) * | 1970-08-06 | 1976-05-04 | Zaidan Hojin, Seisan Kaihatsu Kagaku Kenkyusho | Method for manufacturing medical articles composed of silicone rubber coated with collagen |
US4851009A (en) * | 1985-12-16 | 1989-07-25 | Corvita Corporation | Crack prevention of implanted prostheses |
US4718905A (en) * | 1986-08-13 | 1988-01-12 | Freeman Jerre M | Haptic element using ion beam implantation for an intraocular lens |
Cited By (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5851231A (en) * | 1990-02-28 | 1998-12-22 | Medtronic, Inc. | Intralumenal drug eluting prosthesis |
US5997468A (en) * | 1990-02-28 | 1999-12-07 | Medtronic, Inc. | Intraluminal drug eluting prosthesis method |
US5545208A (en) * | 1990-02-28 | 1996-08-13 | Medtronic, Inc. | Intralumenal drug eluting prosthesis |
US6004346A (en) * | 1990-02-28 | 1999-12-21 | Medtronic, Inc. | Intralumenal drug eluting prosthesis |
US5871535A (en) * | 1990-02-28 | 1999-02-16 | Medtronic, Inc. | Intralumenal drug eluting prosthesis |
US5725567A (en) * | 1990-02-28 | 1998-03-10 | Medtronic, Inc. | Method of making a intralumenal drug eluting prosthesis |
US5851217A (en) * | 1990-02-28 | 1998-12-22 | Medtronic, Inc. | Intralumenal drug eluting prosthesis |
US5451428A (en) * | 1991-05-21 | 1995-09-19 | Hewlett-Packard Company | Method for pretreating the surface of a medical device |
US5308704A (en) * | 1991-08-20 | 1994-05-03 | Sony Corporation | Cell adhesive material and method for producing same |
US5837275A (en) * | 1992-05-19 | 1998-11-17 | Westaim Technologies, Inc. | Anti-microbial materials |
US6238686B1 (en) | 1992-05-19 | 2001-05-29 | Westaim Technologies | Anti-microbial coating for medical devices |
US5753251A (en) * | 1992-05-19 | 1998-05-19 | Westaim Technologies, Inc. | Anti-microbial coating for medical device |
US5681575A (en) * | 1992-05-19 | 1997-10-28 | Westaim Technologies Inc. | Anti-microbial coating for medical devices |
US5770255A (en) * | 1992-05-19 | 1998-06-23 | Westaim Technologies, Inc. | Anti-microbial coating for medical devices |
US5958440A (en) * | 1992-05-19 | 1999-09-28 | Westaim Technologies, Inc. | Anti-microbial materials |
US5985308A (en) * | 1992-05-19 | 1999-11-16 | Westaim Technologies, Inc. | Process for producing anti-microbial effect with complex silver ions |
US5334201A (en) * | 1993-03-12 | 1994-08-02 | Cowan Kevin P | Permanent stent made of a cross linkable material |
US5607463A (en) * | 1993-03-30 | 1997-03-04 | Medtronic, Inc. | Intravascular medical device |
WO1995031944A1 (en) * | 1994-05-20 | 1995-11-30 | Vec Tec, Inc. | Methods rendering grafts nonthrombogenic and substantially nonimmunogenic |
US5906824A (en) * | 1996-05-17 | 1999-05-25 | Sony Corporation | Antithrombogenic material and method for producing the same |
US5891192A (en) * | 1997-05-22 | 1999-04-06 | The Regents Of The University Of California | Ion-implanted protein-coated intralumenal implants |
WO1998052623A1 (en) * | 1997-05-22 | 1998-11-26 | The Regents Of The University Of California | Ion-implanted protein-coated intralumenal implants |
US8388643B2 (en) | 1999-09-27 | 2013-03-05 | The Regents Of The University Of California | Bioabsorbable polymeric implants and a method of using the same to create occlusions |
US20060058835A1 (en) * | 1999-09-27 | 2006-03-16 | Yuichi Murayama | Bioabsorbable polymeric implants and a method of using the same to create occlusions |
WO2002074354A1 (en) * | 2001-03-16 | 2002-09-26 | Delsitech Oy | Treatment of sols, gels, mixtures or composites of sols and gels, and/or sol-gel derived materials |
US20040121451A1 (en) * | 2001-03-16 | 2004-06-24 | Niko Moritz | Treatment of sols, gels and mixtures thereof |
US20040176838A1 (en) * | 2001-05-21 | 2004-09-09 | Andreas Mucha | Medical device |
WO2002094332A1 (en) * | 2001-05-21 | 2002-11-28 | Qualimed Innovative Medizinprodukte Gmbh | Medical device |
WO2004026355A1 (en) * | 2002-08-30 | 2004-04-01 | Riken | Biological repair material compatible with biological tissue adhesive |
US20060155041A1 (en) * | 2002-08-30 | 2006-07-13 | Yoshiaki Suzuki | Biological repair material compatible with biological tissue adhesive |
US7722934B2 (en) | 2002-08-30 | 2010-05-25 | Riken | Biological repair material compatible with biological tissue adhesive |
US20070185570A1 (en) * | 2003-08-19 | 2007-08-09 | The Chemo-Sero-Therapeutic Research Institute | Material for aneurysm curing |
US20110196415A1 (en) * | 2003-08-19 | 2011-08-11 | Riken | Material for aneurysm curing |
US8268300B2 (en) | 2003-08-19 | 2012-09-18 | Riken | Material for aneurysm curing |
Also Published As
Publication number | Publication date |
---|---|
JP2930329B2 (en) | 1999-08-03 |
CA2023964A1 (en) | 2005-05-03 |
CA2023964C (en) | 2005-05-03 |
JPH03112560A (en) | 1991-05-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5152783A (en) | Antithrombogenic material | |
DE69121586T2 (en) | FLUORED SURFACE OF POLYMER IMPLANTS | |
US4116898A (en) | Non-thrombogenic articles | |
Hiebert et al. | The observation of heparin on endothelium after injection | |
Dickinson et al. | Biodegradation of a poly (α‐amino acid) hydrogel. I. In vivo | |
DE69214466T2 (en) | POLYMER COATING | |
DE60214513T2 (en) | PROCESS FOR SURFACE MODIFICATION | |
Ren et al. | Hemocompatibility evaluation of polyurethane film with surface‐grafted poly (ethylene glycol) and carboxymethyl‐chitosan | |
Galgut et al. | Histological evaluation of biodegradable and non‐degradable membranes placed transcutaneously in rats | |
Karrer | The ultrastructure of mouse lung General architecture of capillary and alveolar walls | |
AU635197B2 (en) | Antimicrobial device and method | |
Miyara et al. | A new antithrombogenic heparinized polymer | |
Laurencin et al. | Poly (anhydride) administration in high doses in vivo: studies of biocompatibility and toxicology | |
Nair | Currently practised sterilization methods-some inadvertent consequences | |
CA1127025A (en) | Anti-thrombogenic retentive catheter | |
FI904254A0 (en) | FOERFARANDEN OCH SAMMANSAETTNINGAR FOER BEHANDLING AV PATOLOGISKA HYDROFOBISKA EFFEKTER I BIOLOGISKA FLUIDER. | |
FI104324B1 (en) | Process for the preparation of therapeutically useful, insoluble swellable polymeric allylamammonium derivative | |
EP0561507A1 (en) | Method for grafting preformed hydrophilic polymers onto hydrophobic polymer substrates | |
NO872675D0 (en) | Means for inhibiting the disposal of transplanted organs | |
Lora et al. | Biocompatible polyphosphazenes by radiation-induced graft copofymerization and heparinization | |
EP0602056A1 (en) | Method for protecting prostheses and temporarily or permanently implantable materials from bacterial colonisation and infection | |
Wach et al. | Nerve guidance channels based on PLLA–PTMC biomaterial | |
CA2028069C (en) | Anti-thrombogenic, and/or anti-microbial composition | |
Chen et al. | Grafting copolymerization of acrylamides onto preirradiated PP films | |
Xie et al. | Surface modification of poly (vinyl chloride) for antithrombogenicity study |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: RIKAGAKU KENKYSHO, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:SUZUKI, YOSHIAKI;KUSAKABE, MASAHIRO;IWAKI, MASAYA;AND OTHERS;REEL/FRAME:005474/0217 Effective date: 19900921 Owner name: SONY CORPORATION, A CORP. OF JAPAN, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:SUZUKI, YOSHIAKI;KUSAKABE, MASAHIRO;IWAKI, MASAYA;AND OTHERS;REEL/FRAME:005474/0217 Effective date: 19900921 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
REFU | Refund |
Free format text: REFUND OF EXCESS PAYMENTS PROCESSED (ORIGINAL EVENT CODE: R169); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FEPP | Fee payment procedure |
Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 12 |